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how long it takes to grow weed outdoors

Marijuana light cycle: 12 hours a day

Generally speaking, it takes anywhere from 10-32 weeks, or about 3-8 months, to grow a weed plant from seed. It’ll be quicker if you start with a clone or an autoflower seed.

Marijuana light cycle: indoor—16 hours a day; outdoor—at least 6 hours of direct sunlight (“full sun”), plus several hours indirect sunlight

Be very careful to not overwater the plant in its seedling stage—its roots are so small, it doesn’t need much water to thrive.

Vegetative stage

Harvest happens sometime between September and November. This depends on your local climate, as well as the weather that particular year—one year it could be the end of September, the next, end of October, and growers in the Pacific Northwest will have to pull down their crops earlier than those in Northern California.

The growth stages of marijuana can be broken down into four primary stages from seed to harvest:

Cannabis plants are considered seedlings until they begin to develop leaves with the full number of blades on new fan leaves. A healthy seedling should be a vibrant green color.

How long does it take to grow a marijuana plant?

Seedling stage length: 2-3 weeks

Seed germination length: 3-10 days

How long it takes to grow weed outdoors

The flowering (or bloom) stage begins when you switch your lights to a 12 hours on and 12 hours off schedule and continues until harvest. As mentioned, your plants will double in size during this stage of growth.

Starting with clones obviously saves a bit of time over starting with seeds.

We’ll go into more detail on how to speed up the process below. First, let’s try to answer the primary question as best we can.

Time Required: 5 to 16 weeks (or more for select strains)

Why would you want this period to last any longer than it has to, though?

The bloom stage can be broken up into several distinct sub-stages. You can read about that in our article on flowering time, which also covers how to know when it is time to harvest your buds.


Most reputable online seed banks are located in Europe, but some have US offices, which cuts down on shipping times. Our article on the best places to buy marijuana seeds has everything you need to find the best seed bank.

If you provide your plants the perfect conditions, they will grow faster, and produce buds faster as well. This means you need to give them the right type of lighting (quantum board LED lights from HLG are perfect; if you are on more of a budget, check out Spider Farmer), a good growing medium, the right amount of water and nutrients, and the right temperature and humidity.

How long it takes to grow weed outdoors

This gives you the freedom to choose the exact strain you want without any worry about how long it will take. This gives you the freedom to grow some strains that otherwise are inaccessible to growers who are worried about timeframes.

Counter-clockwise from top left: Alaskan Purple Auto, White Widow Max Auto, Candy Kush Auto, Pink Kush CBD 30:1 (short purple plant), Zkittlez Auto, Gelato Auto

What if time is not an issue?

The average indoor cannabis grow takes 3-4 months from seed to harvest. The full range is 2-6 months and depends on the strain and desired size of plants.

Long Anwer:

Here are some of great auto-flowering strains I’ve personally grown and recommend. These are all ready to harvest 8-10 weeks from germination:

You want to get an auto-flowering strain. These cannabis plants automatically start making buds after about a month from germination, and are ready to harvest by the time they’re 2 or 3 months old.

Important Milestones in the Marijuana Plant’s Life

2-3 months from seed to harvest

3-5+ months from seed to harvest